http://www.seaslugforum.net/factsheet.cfm?base=pupasoli
http://www.conchology.uunethost.be/GENERAL/Cyberconchology/SuperConch/Gastropoda/ACTEONIDAE.html
http://shell.kwansei.ac.jp/~shell/pic_book/data08/r000737.html
http://rfbolland.com/okislugs/pupasoli.html
http://gastropods.com/8/Shell_4028.shtml